YouTube System Design

Quick Reference: Netflix | Step 4: CDN | Step 5: Video Streaming

Quick Reference

Scale: 2B+ users, 500+ hours uploaded/minute, 1B+ hours watched/day

Key Components: Video storage, CDN, transcoding, recommendations, search

Challenges: Storage, bandwidth, transcoding, recommendations at scale

Clear Definition

YouTube is a video sharing platform requiring massive storage, global content delivery, video processing, and recommendation systems at unprecedented scale.

šŸ’” Key Insight: YouTube uses CDN for delivery, distributed storage, and sophisticated recommendation algorithms.

Core Concepts

Architecture Components

  1. Video Upload: Store raw videos
  2. Transcoding: Convert to multiple formats/qualities
  3. CDN: Distribute videos globally
  4. Recommendations: ML-based video suggestions
  5. Search: Index and search video metadata

Key Design Decisions

  • CDN: Distribute videos globally for low latency
  • Transcoding: Multiple quality levels for adaptive streaming
  • Storage: Distributed object storage (Google Cloud Storage)
  • Database: Sharded for scale

Use Cases

  • Video upload and storage
  • Video playback and streaming
  • Recommendations and discovery
  • Search and metadata

Best Practices

  1. CDN: Distribute content globally
  2. Adaptive Streaming: Multiple quality levels
  3. Caching: Cache metadata and thumbnails
  4. Sharding: Shard databases for scale

Quick Reference Summary

YouTube: Video platform requiring massive scale.

Key Components: Storage, CDN, transcoding, recommendations.

Key Design: CDN distribution, adaptive streaming, sharded databases.

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